Rotary material reducing machine



Aug. '1, 1933. J. T. FOWLER ROTARY MATERIAL REDUCING MACHINE Filed Jul 25. 1930 2 Sheets-Sheet. 1

II=I 1g 2 B E E 5 J06 TFow/er Aug. 1, 1933 J. WL 1,920,945

' ROTARY MATERIAL REDUCING MACHINE Filed July 25, 1930 2 Sheets-Sheet. 2

a O I I 1 Q 4 IO o n. 2| lug. 6

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//YVENTOR Jo/m TFow/er Patented Aug. 1, 1933 sarsnr OFFlCE ROTARY MATERIAL REDUCING MACHINE John T. Fowler, Columbus, Ohio, assignor to The Jeffrey Manufacturing Company,

Columbus,

Ohio a Corporation of Ohio Application July 25, 1930. Serial No. 470,717

1'7 Claims. (01. 8311) The present invention relates to a machine particularly adapted for use in shredding fibrous materials, such as straw in bales, corn stalks, wood shavinga bagasse, pulp in laps or sheets,

5 and other similar materials not of high specific gravity, but heavy'in the masses ordinarily fed to the machine, for example, wet wood chips.

*The common type of swing hammer machine has not proven satisfactory in the handling of the above and similar materials. In this type of machine the hammers are held out in working relation to the breaker plate or abutment bar by centrifugal action, and in reducing fibrous materials with the light weight hammers as heretofore used, the centrifugal eiiect is not sufiiciently great to support the weight of the mass, take the impact shocks common with intermittent feed, or cut through the material in the screen'bar section without being forced back out of radial position. a r Unless the rotor be of excessively massive construction and revolved at relatively high speed, the hammers flying back and continually vibrating will cause excessive wear on the mounting rods and their supporting apertures, and ultimately the breakage of hammers and stop pins. Also, when the hammers are forced back the machine chokes up, causing a, rise in power consumption and extra strain on the machine as a whole. The choking up results in less capacity and a-coarser product since the machine slows down and the hammers are less effective, since they are not in correct relation to the breaker plate, screen bars, and so forth.-

5 If, on the otherhand, heavy hammers are used and the rotor is'revolved at relatively high speed, the mass of material will be supported on the rotor but proper shredding or cutting action will not take place due to the thickness of the hammers and the forcing of material through the screen bars before it is sufiiciently reduced.

The'principal object of the present invention is the provision of a rotor which will withstand the impact shocks and support the weight of the masses and yet will be sufiiciently flexible to reduce the material. To this end I provide my improved rotor with what I shall term flotation hammers which are adapted to support the material, until it is sufficiently torn apart to enable the taking place of shredding action in the screen section, and I provide separate reducing hammers to accomplish this shredding action. The flotation hammers must be such as to resist tangentially directed impacts, thus being capable of floating the material on the rotor, while the reducing hammers may have relatively great yieldability under the impacts as compared to the flotation hammers. To provide this differential factor, the flotation hammers may be rigidly mounted on the rotor andthe reducing hammers 0 freely pivoted to the rotor for centrifugal projection; While I shall refer to the rigid hammers as flotation hammers, and to the swing hammers as reducing hammers, the two functions are, of course, somewhat divided between the two sets 5 of hammers, although for all practical purposes, the rigid hammers may be assumed to be the floating instrumentalities and the swing hammers the material reducing instrumentalities. As will appear hereinafter, the two sets of hammers may be variously related in order to secure various effects, and it will be understood that while my improved rotor is particularly adapted for use in shredders, it is also adapted for use in pulverizers and crushers. 7

Without further discussion of the general aspects of the invention, I shall proceed to describe it with reference to the accompanying drawings, in which:

Figure 1 is a cross section of the machine embodying my invention,

Figure 2 is a developed plan of the rotor of Figure 1,

Figure 3 is a developed plan of a rotor with a modified arrangement of hammers,

Figure 4 is a cross section of the machine provided with a modified type of hammer.

Figure 5 is a developed plan of a rotor provided with hammers of the type shown in Figure 4 but in modified arrangement, and

Figure 6 is a developed plan of a rotor provided with hammers similar to those of the machine of Figure 4, but in modified arrangement.

Referring to the drawings, reference numeral 10 designates generally a rotor casing provided with an upwardly open hopper 11, a breaker bar 12, and a screen bar section 13. Suitably journaled for rotation in the casing is a shaft 14 to which is keyed a rotor body comprising circular discs 15 held in spaced relation by collars, as at 16, and supporting in marginal apertures a plurality of mounting rods 17 around shaft 14.

The flotation hammers are designated at 18, and as here shown are provided with three arms, of which two are adapted to be engaged on adjacent rods 17 with the third in rigid radial posi tion. To the rear of each hammer 18 is mounted a swing hammer 19 on the next succeeding rod 17, the hammers substantially filling the spaces between the discs. As may be seen from Figure 2, the flotation hammers 18 and reducing hammers 19 are mounted in alternating rows extending axially of the rotor, and all the rod spaces are occupied by hammers. This arrangement is well adapted for use in breaking bales, slabs, or

- laps, or bulky masses generally of relatively heavy According to Figure 3, certain of the rodspacesmaterial where an essentially shredding action is not a. prime requisite.

tremely heavy and a coarser product is desired.

The hammers being spaced further apart, it follows that their action'is not so violent, and therefore the material is not reduced to the same extent as when the rotor of Figures 1 and 2 is used.

When the feed is relatively light andyor a see product is required, the rotor is preferably constituted as shown inFigures 4, 5 or 6. According to the embodiment of the invention shown in these latter figures, the machine casing and rotor body are of the same standard size and form as shown inFigurel, but the hammers are much thinner than those shown in Figure 2 and only partially fill the spaces between the discs. While the thickness of the hammers may be varied in accordance with requirements, they are shown in Figures 5 and 6 as being substantially half the width of the hammers of Figure 2.

In Figures 4 to 6, the flotation hammers are designated at 20 and the swing hammers at 21. According to Figure 5, the rigid hammers 20 and swing hammers -2l are arranged in alternating rows extending in the axial direction of the rotor, all the rod spaceslbeing occupied. In order to 7 position the hammers between the discs, spacing elements or collars 22 are strung on the rods. Referring to the upper row of hammers 20 in Figure 5, it will be noted that collars 22 are arranged so as to position the hammers against the right hand faces of the discs, while the collars 22 associated with the swing hammers 21 position the later against the left hand disc faces. Thus the two sets of hammers are retained in non-tracking relation, hammers 20 still protecting hammers 21 from impacts. This arrangement is used when the material is comparative- 1y light in itself and the feed is not too heavy,- and when it is desired to secure a finer product than results from the hammers and their arrangement as shown in Figures 2 and 3. A similar effect is secured with the hammer arrangement as shown in Figure 4. It will be noted from this latter figure that groups of hammers, each group comprising a rigid hammer and a swing hammer, are arranged in non-tracking relation around the rotor between adjacent discs, one group being disposed-adjacent the left hand disc face, the next adjacent the right hand disc face, and so forth. 7

' According to Figure 6, some of the rod spaces are left free with the result that each adjacent two rows of rigid and swing hammersare staggered relative to the succeeding two rows, thus forming groups of hammers, each comprising a leading rigid hammer and a trailing swing hammer in non-tracking relation. This arrangement is desirable in reducing more friable material, and of course the feed cannot be so heavy as when .the otherarrangements are used.

In Figures 5 and. 6, both the rigid and swing hammers are shownas being of substantially the same thickness but it is obvious that they may be of different thickness and may be variously arranged on the rods to meet various conditions.

It will be understood that many changes in structure and arrangement of parts may be made without departing from the invention, and accordingly I do not limit myself except as in the following claims.

I claim:

,L; In a machine of the class described, a casing having anupwardly directed feed opening, a'rotor body in said casing, said rotor bodycomprising 'a' numberiof spaced coaxial discs and a series of rods supported about the axis of the "discs in apertures of said discs, a number of radially ojectl g flotation hammers mounted on said rods between the discs for floating material fed meretc' through said opening, and a number of centrifugally projected material reducing hammers pivoted to said rods between the discs and having relatively great yieldability under tangentially directed impacts as compared to the flotation hammers, said material reducing hammers only partially filling the spaces between their adjacent discs.

2. In a machine of the class described, a casing having an upwardly directed feed opening, a rotor body in said casing, said rotor body comprising a number of spaced coaxial discs and a series of rods supported about the axis of the discs in apertures of.said discs, a number of radially'projecting flotation hammers mounted onsaid rods between the discs for floating material fed thereto through said opening, and a number of cen trifugally projected material reducing hammers tially filling the spacesbetween their adjacent discs, and spacing elements positioning said material reducing hammers relative to their adjacent discs.

3. In a machine of the class described, a casing having an upwardly directed feed opening, a rotor body in said casin said rotor body com prising a number of spaced coaxial discs and a. series of rods supported about the axis of the discs in apertures of said discs, a number of radially projecting flotation hammers mounted on said rods between the discs for floating material fed thereto through said opening, and a number of centrifugally projected material reducing hammers pivoted to said rods between the discs and having relatively great yieldability under tangentially directed impacts as compared to the flotation hammers, said flotation and material reducing hammers only partially filling the spaces between their adjacent discs. 4 I

4. In a machine of the class described, a casing having an upwardly directed feed opening, a rotor body in said casing, said rotorbodycomprising a number ofspacedcoaxialdiscs and a series of rods supportedabout the axis of the discs in apertures of said discs,- a number of radially projecting flotation hammers mounted on said rods between the dlscs'for floating material fed thereto through said openingsyand 'a number of centri-fugally proj'ect'e'dinaterial reducinghamm'ers pivoted to said rods between the discs and having relatively great yieldabili'ty under tangentially directed impacts as compared to the notation hammers, said flotation and "ma teri'al reducing hammers onlypartially'filling' the spaces between their adjacent discs, and spacing 5. In a machine of the class described, a casing having an upwardly directed feed opening, a rotor body in said casing, said rotor body comprising a number of spaced c'oaxialdiscs and a series of rods supported about the axis of the discs in apertures of said discs, a number of radially projecting flotation hammers mounted on said rods between the discs for floating material fed thereto through said opening, and a,

number of centrifugally projected material reducing hammers pivoted to said rods between the discs and having relatively great yieldability under tangentially directed impacts as compared to the flotation hammers, said flotation and material reducing hammers only partially filling the spaces between their adjacent discs, said ham-- mers being arranged in alternating rows extending axially of the rotor body.

6. In a machine ofv the class described, a casing having an upwardly directed feed opening, a rotor body in said casing, said rotor body comprising a number of spaced coaxial discs and a series of rods supported about the axis of the discs in apertures of said discs, a number of radially projecting flotation hammers mounted on said rods between the discs for floating material fed thereto through said opening, and a number of centrifugally projected material reducing hammers pivoted to said rods between the discs and having relatively great yieldability under tangentially directed impacts as compared to the flotation hammers, said flotation and material reducing hammers only partially filling the spaces between their adjacent discs, said hammers being arranged in alternating rows extending axially of the rotor body with the hammers of each two adjacent rows staggered relative to the hammers of the next two adjacent rows to discs in apertures of said discs, a number of radially projecting flotation hammers mounted on said rods between the discsfor floating material fed thereto through said opening, and a number of centrifugally projected material reducing hammers pivoted to said rods between the discs and having relatively great yieldability under tangentially directed impacts as compared to the flotation hammers, said flotation and material reducing hammers only partially filling the spaces between their adjacent discs, said hammers being arranged in alternating rows extending axially of the rotorbody, and spacing elements positioning said hammers relative to their adjacent discs with adjacent flotation and material reducing hammersbetween the same discs in non-tracking relation. 7

8. In a machine of the class described, a rotor body, rigidly mounted hammers projecting radially from said rotor and acting to floatmate-.

I rial on the rotor upon rotor rotation, and swing hammers pivoted to said rotor and adapted to be substantially radially projected upon rotor rotation to yield under tangential reducing impact upon said material.

9. In a machine of the class described, a rotor body, rigidly mounted hammers projecting radiallyfrom said rotor, and: swing hammers pivoted to said rotor and adapted to be substantially radially projected upon rotor rotation, the rigid hammers and swing hammers being arranged in alternating rows extending axially of the rotor body.-

10. In a machine of the class described, a 1'0- tor body, rigidly mounted hammers projecting radially fromsaid'rotor, and swing hammers pivoted to said rotor and adapted to be substantially radially projected upon rotor rotation, the rigid hammers and swing hammers being arranged in alternating rows extending axially of the rotor body with the hammers of each row staggered relative to the hammers of the adjacent rows.

11. In a machine of the class described, a rotor body comprising a number of spaced coaxial discs and a series of rods supported about the axis of the discs in apertures of said discs, hammers rigidly mounted on said rods between the discs, and swing hammers pivoted to said rods between the discs and only partially filling the spaces between their adjacent discs.

12. In a machine of the class described, a rotor body comprising a number of spaced coaxial discs and a series of rods supported about the axis of the discs in apertures of said discs, hammers rigidly mounted on said rods between the discs, and swing hammers pivoted to said rods between the discs and only partially filling the spaces between their adjacent discs, and spacing elements positioning said swing hammers relative to their adjacent discs.

13. In a machine of the class described, a rotor body comprising a number of spaced coaxial discs and a series of rods supported about the axis of the discs in apertures of said discs, hammers rigidly mounted on said rods between the discs, and swing hammers pivoted to said rods between the discs, the rigid and swing hammers only partially filling the spaces between their adjacent discs. r

14. In a machine of the class described, a rotor body comprising a number of spaced coaxial discs and a series of rods supported about the axis of the discs in apertures of said discs, hammers rigidly mounted on said rods between the discs, and swing hammers pivotedrto said rods between the discs, the rigid and swing hammers only partially filling the spaces between their adjacent discs, and spacing elements positioning said hamonly partially filling the spaces between their adjacent discs, said hammers being arranged inalternating rows extending axially of the rotor body.

16. In a machine of the class described, a rotor body comprising a number of spaced coaxial discs and a series of rods supported about the axis of the discs in apertures of said discs, hammers rigidly mounted on said rods between the discs, and swing hammers pivoted to said rods between the discs, the rigid and swing hammers only partially filling the spaces between their adjacent discs, said hammers being arranged in alternating rows extending axially of the rotor body with the hammers of each two adjacent rows staggered relative to the hammers of the between the discs, therigid and. swing hammers only partially filling the spaces between their'adjacent discs, said hammers .being arranged in alternating rows extending axially of the rotor .body, and spacing elements positioning said hammers relative to their adjacent discs with adjacent rigid and swing hammers between the same discs in non-tracking relation.

v JOHN T. FOWLER. 

